1. Field of the Invention
The present invention relates to the use of soil additives and mulches to promote the growth of vegetables and other desirable vegetation.
2. Description of the Prior Art
Man has historically sought to improve the agricultural productivity of crops and other desirable vegetation, such as flowers. Many soil additives and mulches have been developed in attempts to increase crop yield. Such materials function as either fertilizers, mulches or pesticides. Fertilizers contain particular desirable chemical compounds and are mixed with or diseminate into the soil to enrich the soil with required crop nutrients. Mulches, on the other hand, usually are formed of loosely packed material which is generally spread upon the surface of the soil or mixed in surface soil to aid in protecting the roots of crops. Pesticides are frequently employed to protect crops from insects, such as potato beetles, aphids and other pests. The expenditures involved in providing such soil additives, fertilizers and insecticides throughout the United States and elsewhere is enormous.
In the past, there have been repeated attempts to provide effective agricultural soil conditioners at a reduced cost. Mulches comprised of hay or straw have been used to promote the growth of edible crops, (such as potatoes). In the spring, seed potatoes may be laid on top of unharvested crop remnants, such as corn stalks, strawberry plant leaves and hay left from the previous growing season. The seed potatoes may be mulched with a heavy hay blanket and grown therein.
Other systems of crop enhancement have sought to employ wood products as a soil treatment or mulch. In one such system it is suggested that unprocessed wood chips scattered about plants and vegetables may provide an effective mulch. Other systems employ more exotic treatment of wood products before utilizing them as an aid to agriculture. For example, it has been suggested that ground pine bark or sawdust may be mixed with a microbial source, such as ground manure, sewage sludge or industrial waste, and subjected to aerobic decomposition. After processing involving heating and agitation, the resulting material is used as a soil conditioner or mulch. Another suggestion has been to utilize finely shredded fiber and dust-like particles of the bark of the redwood tree as a fertilizer and soil conditioner. However, the high acidity content of wood and wood products when used as a soil conditioner has been recognized and has been considered to be undesirable, although sometimes tolerable. For this an other reason, wood products, when they are used, are frequently subjected to extensive pretreatment prior to application to the soil. For example, the shredded redwood fiber and bark has been reacted with ammonia at elevated pressures and temperatures to improve its nitrogen content. A costly autoclave is required in this connection, however, and the batch processing of redwood bark and dust is ill suited to the large quantities required of soil treatment materials. On the other hand, redwood barks has also, in the past, been used as a filtering agent for sewage waste systems and, after drying, utilized as a fertilizer and soil conditioner. Again, however, expensive and time consuming treatment has been required to transform the redwood material from its natural state to a material useful for application to agricultural soil.